Sleep inversion or sleep-wake inversion is a reversal of
sleeping tendencies. Individuals experiencing sleep-wake inversion exchange
diurnal habits for
nocturnal habits
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite.
Nocturnal creatures generally have highly developed sen ...
, meaning they are active at night and sleep during the day. Sleep-wake inversion, when involuntary, can be a sign of a serious disorder.
Presentation
Individuals with the delayed sleep phase type of the disorder exhibit habitually late sleep hours and an inability to change their sleeping schedule consistently. They often show sleepiness during the desired wake period of their days. Their actual phase of sleep is normal. Once they fall asleep, they stay asleep for a normal period of time, albeit a period of time that starts and stops at an abnormally late time.
Causes
Sleep inversion may be a symptom of
elevated blood ammonia levels and is often an early symptom of
hepatic encephalopathy. Sleep inversion is a feature of
African trypanosomiasis
African trypanosomiasis, also known as African sleeping sickness or simply sleeping sickness, is an insect-borne parasitic infection of humans and other animals. It is caused by the species ''Trypanosoma brucei''. Humans are infected by two typ ...
, after which the disease takes its common name, "African sleeping sickness"; sleep-wake cycle disturbances are the most common indication that the disease has reached the stage where infection spreads into the central nervous system.
See also
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Jet lag
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Shift work sleep disorder
Shift work sleep disorder (SWSD) is a circadian rhythm sleep disorder characterized by insomnia, excessive sleepiness, or both affecting people whose work hours overlap with the typical sleep period. Insomnia can be the difficulty to fall asleep ...
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Circadian rhythm
A circadian rhythm (), or circadian cycle, is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., Endogeny (biology), endogeno ...
*
Delayed sleep phase disorder
*
Encephalitis lethargica
Encephalitis lethargica is an atypical form of encephalitis. Also known as "sleeping sickness" or "sleepy sickness" (distinct from tsetse fly-transmitted sleeping sickness), it was first described in 1917 by neurologist Constantin von Economo a ...
*
Lethargy
References
{{Reflist
External links
* American Psychiatric Association. ''Diagnostic and Statistical Manual of Mental Disorders.'' 4th edition, text revised. Washington, DC: American Psychiatric Association, 2000.
* Buysse, Daniel J., Charles M. Morin, and Charles F. Reynolds III. ''Sleep Disorders''. In ''Treatments of Psychiatric Disorders,'' edited by Glen O. Gabbard. 2nd edition. Washington, DC: American Psychiatric Press, 1995.
* Hobson, J. Allan, and Rosalia Silvestri. "Sleep and Its Disorders." In ''The Harvard Guide to Psychiatry,'' edited by Armand M. Nicholi, Jr., M.D. Cambridge, MA: Belknap Press of Harvard University Press, 1999.
* Thorpy, Michael J., M.D., and Jan Yager, Ph.D.''The Encyclopedia of Sleep and Sleep Disorders.'' 2nd edition. New York: Facts on File, 2001.
American Sleep Disorders Association 6301 Bandel Road NW, Suite 101, Rochester, MN 55901.
* http://www.minddisorders.com/Br-Del/Circadian-rhythm-sleep-disorder.html#ixzz3tkBVLE9P
Sleep medicine
Sleep disorders